| 摘要 |
<p>PURPOSE:To permit incorporation of an electric power controlling device easily to an existing power receiving installation by penetrating the electric wire of an ammeter connected to a current transformer on the secondary side of a power transformer into a core installed with a Hall element in its gap. CONSTITUTION:Electric power is supplied from a power transformer 1 of star- delta connection to 3-phase load 2, and an indicating type ammeter 4 is connected to a potential transformer 3 provided to the secondary side line of the transformer 1. One end of the ammeter 4 is penetrated through or wound a number of times into a gapped core 5 of ferrite or the like and is connected to the terminal on the opposite side of the transformer 3. The output voltage of a Hall element 6 disposed in the gap of the core 5 is applied via an operational amplifier 8 to an A/D converter 9, and the A/D converted output is displayed in a digital display part 10 such as LED. Thereby, a control meter for operation of the transformer of an existing cubicle or the like is installed with simple construction work.</p> |
